The "fixed" windows on our 1968 Airstream Sovereign
( the smaller rectangular windows below and above our "normal" crank-out windows in front living area) leak and we are pulling them out one by one to re-set and re-caulk them. On the interior of these fixed windows, there is a glazing spline that looks to have shrunk with age (please see picture). Has anyone replaced these glazing splines or have a source for them or a similar product that would work? Any advise or suggestions would be greatly appreciated!